Split cloning and checkout into two

Dockerfile

@@ -29,5 +29,9 @@ ENV XDG_RUNTIME_DIR=/tmp
 ENV QT_QPA_PLATFORM=wayland
 ENV MAKEFLAGS=-j8
 
+# Keep Qt source code as part of the image to avoid duplication
+COPY scripts/clone-qt.sh /home/build/scripts/clone-qt.sh
+RUN scripts/clone-qt.sh
+
 COPY scripts/ /home/build/scripts
 CMD "./scripts/run.sh"

scripts/checkout-qt.sh

+#!/bin/bash
+set -ex
+srcdir=$(pwd)/qt5
+qt5_rev=${QT_DOCKERTEST_QT5_REV:-5.11}
+
+git fetch --depth 1 origin "$qt5_rev"
+git checkout FETCH_HEAD
+git submodule update --init -- qtbase qtxmlpatterns qtdeclarative qtwayland
+
+if [[ -v QT_DOCKERTEST_QTWAYLAND_REV ]] ; then
+    cd "$srcdir/qtwayland"
+    git fetch --depth 1 origin "$QT_DOCKERTEST_QTWAYLAND_REV"
+    git checkout FETCH_HEAD
+fi

scripts/run.sh

 #!/bin/bash
 set -ex
-time scripts/clone-qt.sh
-echo Finished cloning
+#time scripts/clone-qt.sh
+#echo Finished cloning
+time scripts/update-qt.sh
+echo Finished preparing sources
 time scripts/build-qt.sh
 echo Finished building
 time scripts/build-qtbase-tests.sh